We all know the typical algorithm for our patients having diabetes: Maintain healthy blood sugar and pressure control, get annual dilated eye examinations, and receive laser or anti-VEGF therapy if and when they develop vision-threatening diabetic retinopathy (DR). Although these treatments save vision, unfortunately, this “counsel, watch, and wait to treat” approach does not always result in optimal outcomes and without significant expenditure of resources.
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Evidence shows that as many as 20 percent of newly diagnosed patients with type 2 diabetes have some degree of DR already,1 and that early, tight control of blood glucose (as reflected by its three-month average, glycosylated hemoglobin or HbA1c) lowers both the incidence and progression of DR. Still, about 50 percent of patients have HbA1c levels above 7 percent,2 and while healthy metabolic control lowers the risk of diabetes complications, there are many patients who ultimately achieve good control and end up needing destructive photocoagulation or a series of injections into the eyes. This begs the question: Is there anything more we can do for our patients with diabetes?
DiVFuSS clinical trial
Inspired by a 2011 paper published in IOVS (Kowluru, Beyond AREDS: is there a place for antioxidant therapy in the prevention/treatment of eye disease?),3 I became the principal investigator of a randomized, double-blinded placebo-controlled clinical trial called the Diabetes Visual Function Supplement Study (DiVFuSS) in an attempt to answer these questions. Results were recently published4 and presented at the ARVO Diabetic Retinopathy Meeting at the National Institutes of Health.
Previous work has linked diabetes and diabetic retinopathy to abnormalities of visual function (color vision,5 visual field,6 contrast sensitivity7) as well as to reduced macular pigment.8 Our goal in DiVFuSS was to see if visual function could be improved in patients with diabetes and DR while also assessing potential changes in serum lipids, markers of inflammation and mean glucose.
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Components of the test formula were selected based on previous studies showing some evidence of benefit in cell, animal and/or (limited) human models and consisted of lutein; zeaxanthin; vitamins D, C and E; alpha lipoic acid; coenzyme Q10; curcumin; fish oil; green tea and grape seed extracts, N-acetyl-cysteine; resveratrol; tocotrienols; benfotiamine; Pycnogenol (French maritime pine bark extract, Horphag Research); and low-dose zinc.